I need help fast

so some of u might have already read that my brother cut his whole electrical harness running over is drivers rear fender in his 88 xj. he asked me to help so i re wired all the wires that matched green to green ect. Well there are 4 solid black wires and i dont know which wire goes to the other. those should all be grounds right? does it matter which one goes to what. if it does then how do i figure it out. everything is already working except for the fuel pump, all the blinkers, and the rear wiper which might not have already worked, and the gas gauge.

i just need to get the fuel pump running so that its drivable. please help.

Get an ohmmeter, and test the wires. If, as you suspect, the blacks are all grounds - and you're probably right - the black wire to a component should read open circuit, and the black wire to the source side of the harness should read short circuit to ground. If all the blacks on one side of the cut read short to ground, then they're all grounds, and should be interchangeable.